Martens, Feodor (fyôˈdər märˈtyĭns) [key], 1845–1909, Russian diplomat and authority on international law. He became an official in the foreign ministry in 1868 and was professor of international law at the Univ. of St. Petersburg from 1873 to 1907. He was a representative at many international conferences, including the Hague Conferences of 1899 and 1907, for which he helped lay the foundation. His decisions as arbitrator and his many books contributed much to international law.